I have a small website and wanted an easy-to-install and use PHP tracking script. I tried this one and it is great. It took me 10 minutes to have it all up and runnning. Thats with the time it takes me to upload too!
The only thing I had to alter was displaying the HTML output as I want silent tracking. Which is conveniently stored in a small settings file.
I really don't know much PHP so this package was fantastic.